Species · BCR 4 · BBS 2025 Release · 1966–2024
Black-billed Magpie In BCR 4
Black-billed Magpie in BCR 4 has surged: up 98% on the route-weighted index since 1978.
+98%Since 1978
35Routes In Region
45Years
Notable Signals
long arc increasecomputed index
Black-billed Magpie has surged in BCR 4: up 98% on the route-weighted index since 1978.
Forecast
If the recent trend holds, Black-billed Magpie in BCR 4 is projected to rise about 19% by 2029 — from 1.1 in 2024 to a central estimate of 1.4 (95% range 0.41–2.3). A 5-year backtest shows a typical error of ±12.4%, with 100% of held-out values landing inside the 95% band.
+19%Change by 2029
1.4Projected 2029 index
0.41–2.395% range
±12.4%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 1.3 | 0.40 | 2.3 |
| 2026 | 1.4 | 0.40 | 2.3 |
| 2027 | 1.4 | 0.40 | 2.3 |
| 2028 | 1.4 | 0.41 | 2.3 |
| 2029 | 1.4 | 0.41 | 2.3 |
Routes In BCR 4
| Cohoe | ALASKA | 14 | 2023 |
| Kachemak | ALASKA | 14 | 2024 |
| Anchor River | ALASKA | 13 | 2024 |
| Homer | ALASKA | 9 | 1982 |
| Savage | ALASKA | 7 | 2024 |
| Kalifonsky | ALASKA | 6 | 2023 |
| Toklat | ALASKA | 5 | 2021 |
| Sourdough | ALASKA | 5 | 2022 |
| Slana | ALASKA | 3 | 2024 |
| Goose Bay | ALASKA | 3 | 1982 |
| Hatcher Pass | ALASKA | 3 | 2024 |
| Cottonwood | ALASKA | 3 | 1990 |
| Mccarthy Rd2 | ALASKA | 3 | 1999 |
| Maclaren | ALASKA | 2 | 1986 |
| Wasilla | ALASKA | 2 | 1983 |
| Seven Lakes | ALASKA | 2 | 2023 |
| Ft. Richrdsn | ALASKA | 2 | 2017 |
| Birch Lake | ALASKA | 1 | 2019 |
| Chistochina | ALASKA | 1 | 2022 |
| Monahan | ALASKA | 1 | 2019 |
| Cantwell | ALASKA | 1 | 2015 |
| Skilak Lake | ALASKA | 1 | 1985 |
| Willow | ALASKA | 1 | 2024 |
| Kenny Lake | ALASKA | 1 | 2019 |
| Swan Lake Rd | ALASKA | 1 | 2022 |
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.